What An Average NCAA Tournament Field Looks Like

A popular college basketball preseason topic is debating how many tournament bids conferences will receive the following March.

The ACC punched a conference-best nine bids last season, and expects to a national force again in 2018. The Big Ten was not far behind with seven tickets to the dance for the sixth time in the past nine seasons. On the other hand, the Mountain West, which has had multi-bid seasons in 15 of its first 16 years as a league, has gone two straight campaigns without an at-large bid. The SEC, which placed two teams in the Final Four, has now endured nine seasons without six or more bids, something it did eight times from 1999 to 2008, despite having fewer teams in its league.

Because conference memberships have changed significantly since the turn of the century, finding the percentage of a conference’s membership that reached the NCAA Tournament is a much better indicator of league success than total bids. After all, the number of teams in each conference differ greatly, such as the Big 12’s 10 teams or the ACC’s 15 teams.

The table below indicates the percentage of each conference’s teams that reached the NCAA Tournament, dating back to the 1984-1985 season.

As expected, college basketball’s “power six” conferences (ACC, Big Ten, Big 12, Big East, Pac-12, SEC) have distanced themselves from the rest of college basketball’s other 26 leagues. The ACC and Big Ten are the only conferences that, on average, send more than half of their teams to the Big Dance. Thanks to the Big 12’s recent surge, a six-bid performance in 2018 would propel the league above the 50% mark.

With these percentages in mind, I then found each conference’s percentage over the past four seasons and compared it to their league’s respective all-time averages.

The Big 12 has seen the largest increase in the past four years, improving from an all-time 45.6% mark to 49.8% in the given span. The Big 12 has recorded 27 bids of 40 possible since 2014, the highest total in college basketball.

The SEC, Mountain West, and Conference USA have not been nearly as fortunate. The MWC’s league membership expanded from nine to 11 teams back in 2014, but only seven teams have reached the postseason over the past four seasons. The four year prior, the Mountain West had at least three teams reach the NCAA Tournament. The C-USA hasn’t been a college basketball force in well over a decade, back when it had Marquette, Louisville, Cincinnati, and Memphis in its league, and now it’s downgraded to a consistent autobid-only league in the past five years.

In visual format, this is what an average 68-team NCAA Tournament looks like in 2017 based on each conference’s history, again dating back to 1985.

The ACC paces with an expected seven tournament bids, followed by the Big Ten with six, SEC (5), Big 12 (4), Big East (4), Pac-12 (4), and Atlantic 10 (4). College basketball’s mid-major leagues follow with the American (3), Mountain West (3), Conference USA (3), WCC (2), Missouri Valley (2) and Sun Belt (2). A total of 13 conferences are projected one-bid leagues.